Method for simultaneously throwing and knitting of yarn



Sept. 15, 1964 v E. BIGGERS 3,148,520

METHOD FOR SIMULTANEOUSLY THROWING AND KNITTING 0F YARN Filed Aug. 21, 1957 ATTOR/VEVJ United States Patent 3,148,520 METHOD FQR SKMULTANEOUSLY THRQWING AND KNETTENG 6F YARN Earl H. Biggers, Concord, N.C., assiguor to Patentex, inc, a corporation of New York Filed Aug. 21, 1957, Ser. No. 679,378 Uaims. (Cl. 66-125) This invention relates to the production of stretchable knitted fabrics formed from so-called stretch or lively yarn, and more particularly to a novel method and means by which stretch properties may be applied to the yarn in the course of supplying it directly to a knitting operation and thereby eliminate the special separate treatments of the yarn that have heretofore been necessary to render it stretchable or lively.

It has been common prior practice to produce stretch yarn by a special throwing operation in which continuous filament synthetic resin yarn is run on an uptwister or the like and additionally treated to obtain the particular stretch properties desired. Stretch yarn produced in this manner necessarily further involves subsequent coming or spooling of the treated yarn to place it in suitable form for knitting. In addition to the fact that throwing facilities are normally arranged and operated separately from knitting facilities, and are often located in a separate or independent mill, the special throwing operation employed in stretch yarn production is an involved and time consuming procedure that has added greatly to the cost of producing stretchable knitted fabrics.

According to the present invention yarn may be supplied to a knitting operation directly from a yarn package and have stretch properties imparted thereto in the course of such supply by first leading the yarn through a heating zone and then applying torque characteristics to the yarn, as it is withdrawn from the yarn package for knitting. In this manner all handling of the yarn beyond that required at the knitting operation is eliminated and the production of stretchable knitted fabrics is accordingly not only facilitated advantageously but substantially reduced in cost.

The amount of heating and related physical characteristics of the yarn produced in accordance with this invention may be varied widely by controlling the temperature of the heating device and the rate of drawing of the yarn. For example, if the yarn is heated to a relatively low temperature such as 250 F. and is drawn across a heated surface at a relatively very rapid rate such as 300 yards per minute, the yarn will exhibit a relatively high residual shrinkage. On the other hand, if the temperature of the yarn is maintained relatively high, e.g. 450 F. for example, and the yarn is drawn across the heated element at a relatively low rate, such as 40 yards per minute, then the residual shrinkage in the yarn will be relatively low. Regulation of the temperature, tension, and rate of drawing of the yarn in between these extremes will provide varying degrees of shrinkage, liveliness or torque, or other properties in the yarn. The residual shrinkage of the yarn produced in accordance with this invention enables the production of a stretch stocking or other stretch fabric that has a smooth, flat form, and this is of particular advantage in the production of seamless stretchable stockings.

When the synthetic resin yarn is drawn across the heated element, such as for example a flat heated plate, the heat thus applied apparently tends to soften the yarn but without actually melting the yarn. Other suitable forms of heating devices, such as for example a heated canister or tube may be used instead of a heated plate. It is believed that this softening efiect facilitates a rapid and permanent 'torquing of the yarn when it is drawn across itself in an appropriate manner hereinafter described immediately after heating.

The synthetic resin yarn described herein may be nylon, Dacron, Orlon, Dynel or any of these types of yarns that are adapted to heating and imparting torque to the yarn.

These and other features of the present invention are described in further detail below in connection with the accompanying drawings, in which:

FIG. 1 is a perspective illustration of a representative circular knitting machine arranged for producing stretchable seamless hose in accordance with the present invention;

FIG. 2 is an enlarged fragmentary illustration of the means indicated in FIG. 1 for heating and applying torque characteristics to yarn being knitted;

FIG. 3 is a diagrammatic illustration of the manner in which yarn is handled on the means illustrated in FIG. 2. for having the torque characteristics applied thereto; and

FIG. 4 is a complementary diagrammatic illustration illustrating the manner in which yarn would be handled in having torque characteristics applied thereto opposite to those that would result from the handling indicated in FIG. 3.

Referring now in detail to the drawings, the representative embodiment of the present invention illustrated in FIG. 1 comprises a conventional circular knitting machine equipped with two feed attachments, as indicated generally by the reference numeral 10, which may be of any suitable form, and which normally would incorporate a creel structure 12 arranged to support a yarn supply for the knitting operation. As shown, this yarn supply comprises two cones C and C from which splicing yarns S and S are withdrawn for use in knitting the welt and the foot reinforcements in the hose produced on the machine 10, and two yarn packages P and P from which body yarns Y and Y are withdrawn for knitting. The splicing yarns S and S may be trained for delivery to the knitting head of the machine 10 in any usual manner. The body yarns Y and Y, however, are delivered specially according to the present invention to lead through a heating zone at 14 and then have the previously noted torque characteristics applied thereto at 16 before reaching the knitting head.

A suitable arrangement for delivering the body yarns Y and Y specially in this manner, as indicated generally in FIG. 1, is illustrated more in detail in FIG. 2 of the drawings in which the heating means 14 is shown as comprising an electric hot plate 18 fitted with a temperature indicator at 20 and a thermostat control at 22, and provided with an electrical connection at 24. The hot plate 18 is suitably arranged on a mounting plate 26 in relation to an upright bracket member 28 fitted with guide eyes 30 and carrying tension devices 32 through which the body yarn Y (or Y) may be trained from the yarn package (or P) to lead it over the hot plate 18 as indicated in FIG. 2 at which the yarn is subjected to sufiicient heat for softening it. In the case of nylon yarn a temperature at the hot plate of the order of about 400 F. to 450 F. will normally provide proper yarn softening when regulated in relation to the speed at which the yarn passes across the hot plate which may vary in the general range from about 40 yards per minute to about 200 yards per minute. Beyond the hot plate 18, the mounting plate 26 also carries brackets 34 for supporting the torque applying devicesv 16 which consist of pairs of grooved rolls or pulleys 36 that are rotatably mounted on spacing arms 38 which are in turn mounted for pivotal adjustment at 40 on the support brackets 34. Further guide eyes 42 may also be arranged on the mounting plate 26 for directing the body yarn Y (or Y) from the torque applying devices 1% to the knitting head.

FIG. 3 illustrates diagrammatically the manner in which torque characteristics may be applied to a body yarn Y at the grooved rolls 36 of the torque applying device 16 as disclosed and claimed more in detail in copending application Serial No. 679,479, filed August 21, 1957. In accordance with this copending application, torque characteristics are obtained in the body yarn Y by drawing it across itself immediately after heating. For this purpose, the supplied body yarn Y indicated in FIG. 3 is threaded first over the top grooved roll 36, then downwardly over the paired bottom roll 36 and upwardly inside the yarn reach between the rolls 36, and then over the supplied body yarn Y ahead of the top roll 36 and around both reaches of the body yarn Y to be taken off therefrom for delivery to the knitting head.

It will be noted from the directional arrows in FIG. 3 that the body yarn Y as delivered to the knitting head is drawn across itself, as supplied, from the left side thereof. That is, the body yarn Y leaves the torque applying device 16 at the left side of its supply direction as viewed from above, and the result of this arrangement is to impose a left hand or Z torque direction on the body yarn Y being handled.

FIG. 4 shows a complementary handling of a body yarn Y in which the yarn is threaded oppositely through the torque applying device 16 with a resulting opposite right hand or S torque direction so as to provide for supplying body yarns Y and Y of opposite torque to the knitting machine 10 for knitting in the manner disclosed in U.S. Patent No. 2,771,759.

The result of the present invention is accordingly to provide for conditioning of yarn with stretch properties directly at the knitting means used for converting the yarn into fabric form, so as not only to eliminate the preliminary yarn processing operations that have heretofore been necessary, but also to employ the operating motion of the knitting means for drawing through the required conditioning means as it is supplied for knitting. In this latter connection, the knitting elements may be used to draw the yarn in according to the usual arrangement, or special feed rolls may be driven from the operating motion of the knitting means to deliver the yarn thereto in cases where the tension requirements or knitting cycle make such an arrangement desirable.

Suitable means may be provided for raising the yarn out of contact with the hot plate when the yarn is not being moved across the hot plate, such as, for example, when knitting the welt of a stocking, to prevent damage to the yarn.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise except as defined in the appended claims.

I claim:

1. The method of producing stretchable knitted fabrics which comprises supplying continuous filament synthetic resin yarn to a knitting means, employing the operating motion of the knitting means for drawing the supplied yarn thereto, and leading the supplied yarn through a heating zone and then immediately applying torque characteristics thereto before it reaches said knitting means.

2. Tie method defined in claim 1 and further characterized in that said torque characteristics are applied by drawing the supplied yarn across itself and the torque direction is controlled by selecting the side of the supplied yarn from which it is drawn across itself.

3. Means for producing stretchable knitted fabric comprising in combination with knitting means and means for supporting a yarn supply therefor, a heating device, means for leading yarn from said supply through said device for heating thereby, and means adjacent said device for applying torque characteristics to said yarn immediately after heating and in the course of delivery to said knitting means.

4. Means for producing stretchable knitted fabric comprising, in combination with knitting means, means for supporting a yarn supply therefor, and means employing the operating motion of the knitting means for drawing yarn from said supply thereto; a heating device, means for leading yarn from said supply through said device for heating thereby, and means adjacent said device for drawing said yarn across itself immediately after heating and thereby applying torque characteristics thereto in the course of delivery to said knitting means.

5. The method of knitting stretchable womens seamless hosiery on a circular knitting machine which comprises providing a supply of continuous filament thermoplastic synthetic yarn; drawing said yarn from its supply and passing it through a heating zone located between the supply and the knitting means of said machine, whereby A said yarn is softened; applying torque characteristics to the thus softened yarn and then knitting the thus heated yarn with the torque characteristics therein to obtain said stretch hosiery, the yarn being drawn in continuous form from its supply through said heating zone and the torque application step by said knitting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,247,716 Schellenberg et al July 1, 1941 2,771,760 Burleson Nov. 27, 1956 2,881,504 Billion Apr. 14, 1959 3,035,396 Biggers May 22, 1962 Disclaimer and Dedication 3,148,520.EOWZ H. Biggers, Concord, NC. METHOD FOR SIMULTANE- OUSLY THROWING AND KNITTING OF YARN. Patent dated Sept. 15, 1964. Disclaimer and dedication filed July 31, 1975, by the assignee, Patentew, I no. Hereby disclaims and dedicates to the Public the entire remaining term of said patent.

[Oyficial Gazette October 21, 1975.] 

1. THE METHOD OF PRODUCING STRETCHABLE KNITTED FABRICS WHICH COMPRISES SYUPPLYING CONTINUOUS FILAMENT SYNTHETIC RESIN YARN TO A KNITTING MEANS, EMPLOYING THE OPERATING MOTION OF THE KNITTING MEANS FOR DRAWING THE SUPPLIED YARN THERETO, AND LEADING THE SUPPLIED YARN THROUGH A HEATING ZONE AND THEN IMMEDIATELY APPLYING TORQUE CHARACTERISTICS THERETO BEFORE IT REACHES SAID KNITTING MEANS. 